1. Field of the Invention
This invention pertains to a dispensing system used in the dental art for the controlled application of a viscous material. In particular, this invention relates to dispensing systems having a capsule loaded with a viscous material to be aspirated. More in particular, this invention pertains to a dispensing system wherein the capsule loaded with viscous material to be aspirated is locked in position within the dispenser such that pressure or suction may be applied to the capsule and thereby to the viscous material. Still further, this invention directs itself to a viscous material dispenser having a syringe barrel on which a capsule locking means is slidingly coupled. Still further, the syringe barrel of the viscous material dispenser includes a slot having a helical contour through which a retention spring engages the end of the capsule and secures its position subsequent to rotation of the capsule locking means. Additionally, this invention directs itself to a capsule locking means having a collar slidingly coupled to the syringe barrel of the viscous material dispenser, through which the retention spring passes.
2. Prior Art
Dispensing systems for dispensing viscous dental materials are well-known in the art. The best prior art known to Applicant includes U.S. Pat. Nos. 4,619,613; 4,492,576; 4,330,280; 4,315,743; 4,198,756; 4,084,320; 3,828,434; 3,760,503; 3,618,216; 3,436,828; 3,346,147; 2,903,794; and, 683,075.
Some prior art dispensing systems such as disclosed in U.S. Pat. No. 4,084,320, dispensers for dental amalgum are disclosed which include capsules for the mixing of the amalgum components, and provide dispensers having a plunger to force the material through a nozzle. However, such systems do not provide for the convenience of dispensing the material directly from a mixing capsule, nor do they provide for a means of locking the mixing capsule within the dispenser such that both pressure and suction can be applied to the viscous material to control the volume aspirated through the dispenser nozzle.
In other types of prior art dispensing systems, such as that disclosed by U.S. Pat. Nos. 3,618,216, or 3,346,147, syringe type dental dispensers are disclosed. In these systems, a syringe having a tubular barrel is loaded with the viscous material and dispensed by application of pressure from a plunger. Such systems do not incorporate the dispensing of the viscous material directly from a cartridge or capsule into which the viscous material was prepared. Thus, no means is provided for utilizing pre-packaged materials which may be mixed within the dispensing device and immediately applied. Further, such prior art systems which might accommodate the insert of a capsule containing the viscous material to be dispensed have no means for securing the capsule within the dispenser. Without a means for securing the capsule within the dispenser, such prior art systems would be unable to create the necessary suction to halt the flow of the viscous material subsequent to the application of pressure to aspirate the material. Thus, such prior art systems are unable to provide a controlled volume of viscous material at the dispenser outlet.